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Time Period Converter

Convert days, weeks, months, years and hours at once.

Last updated: 2026/10/17 Calculator Feedback & bug reports
 
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Common periods
Custom (combine any units)
Month and year length

Average: 1 year = 365.2425 days (the Gregorian average), 1 month = 365.2425 ÷ 12 = 30.436875 days, so 1 month = 30.436875 ÷ 7 ≈ 4.348 weeks.

In every unit

–years
–months
–weeks
–days
–hours
–minutes

Time period charts

Months use the average month (30.436875 days). Tap a number to convert it in the calculator above.

How many weeks is a month? (by month length)

LengthIn weeksMonths
28 daysexactly 4 weeksFebruary (common year)
29 days4 weeks 1 dayFebruary (leap year)
30 days4 weeks 2 daysApr, Jun, Sep, Nov
31 days4 weeks 3 daysJan, Mar, May, Jul, Aug, Oct, Dec

Months → weeks

MonthsWeeksDaysReal days
4.35 30.44 28–31
6.52 45.66 —
8.7 60.87 59–62
13.04 91.31 89–92
17.39 121.75 120–123
half a year 26.09 182.62 181–184
39.13 273.93 273–276
1 year 52.18 365.24 365–366

Weeks → months

WeeksDaysMonths
28 0.92
42 1.38
49 1.61
56 1.84
70 2.3
84 2.76
91 2.99
112 3.68
140 4.6
182 5.98
280 9.2
364 11.96

Days → years and months

DaysYears, monthsWeeks, days
about 3 months0.27 years 14 wk 2 d
about 7 months0.55 years 28 wk 4 d
about 1 year1 year 52 wk 1 d
about 1 year 4 months1.37 years 71 wk 3 d
about 2 years 2 months2.13 years 111 wk
about 2 years 9 months2.74 years 142 wk 6 d
about 5 years 6 months5.48 years 285 wk 5 d
about 8 years 3 months8.21 years 428 wk 4 d
about 13 years 8 months13.69 years 714 wk 2 d
about 27 years 5 months27.38 years 1,428 wk 4 d
about 54 years 9 months54.76 years 2,857 wk 1 d
about 273 years 9 months273.79 years 14,285 wk 5 d

Weeks → days (1–52 weeks)

Pregnancy is often described in 4-week months, so 40 weeks is called “10 months”, but in average calendar months it is about 9.2 months.

How to Use

1

Enter a period

Type numbers into years, months, weeks, days or hours. Combine units such as 14 weeks 6 days, or use decimals such as 1.5 months. Common periods take one tap. The page opens with 1 month already converted.

2

Choose how months and years count

Average (1 month = 30.44 days) suits most questions. Choose “30-day month” if you count every month as 30 days, or “Calendar” with a start date to get real dates, such as 1,000 days after your first date.

3

Read, copy and share

Besides the main answer, every unit (years, months, weeks, days, hours, minutes) is listed. “Copy result” copies the answer and “Copy share link” gives a link that opens the same conversion.

What is the Time Period Converter?

A converter for periods between days, weeks, months, years and hours. It answers with decimals and in everyday words, such as “a month is about 4.35 weeks (4 weeks and 2–3 days)” or “1,000 days is about 2 years 9 months”. Because months and years vary in length, you can switch between the average length (1 month = 30.44 days), a 30-day month and the real calendar, and the formula used is shown on screen. Everything runs in your browser.

Features

  • Every unit at onceEnter one value and see years, months, weeks, days, hours and minutes together.
  • Answers in everyday wordsResults such as “4 weeks and 2–3 days”, “about 2 years 9 months” and “142 weeks 6 days”.
  • Three ways to countAverage, 30-day month or real calendar; the calendar mode also gives the end date and weekday.
  • Charts includedWeeks to days (1–52), weeks to months, months to weeks, days to years, and weeks per month length.

Use Cases

  • Checking how many weeks are in a month or six months
  • Turning 1,000 days into years and months for an anniversary
  • Converting pregnancy weeks such as 14 weeks 6 days into days
  • Planning 8- or 12-week programs in months
  • Turning hours, such as 100 hours, into days and weeks

Related date tools

For the weeks and days between two dates, use the Weeks Calculator; for the date N days from today, the Days From Date Calculator; to count days, months and business days between dates, the Date Calculator; and for milestones such as 100 or 1,000 days together, the Anniversary Calculator. Seconds, minutes and other units are in the Unit Converter, and adding up hours and minutes or work hours in the Time Calculator. The math and charts are explained in How many weeks are in a month?

FAQ

How many weeks are in a month?
About 4.35 weeks, or 4 weeks and 2–3 days, on average. The average month is 365.2425 days ÷ 12 = 30.436875 days, and dividing by 7 gives about 4.348 weeks. Real months are 28 to 31 days: February is exactly 4 weeks in a common year, a 30-day month is 4 weeks 2 days and a 31-day month is 4 weeks 3 days.
How many years is 1,000 days?
About 2.74 years, or roughly 2 years 9 months, using average lengths (2 years 8 months 26 days in average months). On the real calendar it depends on the start date: 1,000 days after October 17, 2026 is Friday, July 13, 2029, which is 2 years 8 months 26 days later. In weeks it is 142 weeks and 6 days.
How many weeks are in a year?
A year of 365 days is 52 weeks and 1 day, and a leap year of 366 days is 52 weeks and 2 days. The average year of 365.2425 days is about 52.18 weeks.
How many weeks is 6 months?
About 26.09 weeks (about 182.62 days) on average. Six real months are 181 to 184 days depending on the starting month, which is 25 weeks 6 days to 26 weeks 2 days.
How many months is 8 weeks?
8 weeks is 56 days, or about 1.84 months (about 1 month and 26 days) in average months. 4 weeks (28 days) is a little under a month, about 0.92 months.
How do I convert pregnancy weeks into days?
Multiply the weeks by 7 and add the days: 14 weeks 6 days is 104 days. Pregnancy is counted from the first day of the last period (week 0, day 0), and the due date is 40 weeks 0 days, or 280 days. Use the Due Date Calculator for the due date and the current week.
Why do the average and calendar answers differ?
Because months are 28 to 31 days long. The average mode treats every month as 30.436875 days, so the answer is the same whatever the start date. The calendar mode counts real months from your start date, so the result changes with things like whether February is included. Use average for a general length and calendar for real dates.
When is a 30-day month used?
For rough estimates and for agreements that count every month as 30 days. Note that 12 such months are 360 days, 5 days short of a 365-day year. The month in the Unit Converter also uses 30 days.
How do I find the date N days or weeks from now?
Switch to Calendar and enter a start date to see the end date and weekday. For a quick date N days from today use the Days From Date Calculator, for N weeks the Weeks Calculator, and for lists of milestones such as 100 or 1,000 days the Anniversary Calculator.
Is my input saved?
No. Everything is calculated in your browser and nothing you enter is sent to or stored on a server. A share link contains only the period you entered.

Related Tools

Weeks Calculator Weeks and days between two dates, the date N weeks from today, and this week's number Days From Date Calculator The date N days after or before today or any date, with the day of the week Date Calculator Calculate date ranges, business days & add/subtract dates with JP holiday support Anniversary Calculator Days and months since any date, with milestone anniversaries (100, 1000 days), countdowns, card images and calendar export Unit Converter Convert length, weight, area, volume, temperature, speed & data

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How Many Weeks Are in a Month? Days, Weeks, Months and Years Conversion Chart A month is about 4.35 weeks (4 weeks and 2–3 days). See the math, weeks per month and per year, 1,000 days in years and months, plus easy conversion charts.